Method of treating photographic documents



Patented Dec. 5, 1944 METHOD OF TREATING PHOTOGRAPHIG DOCUMENTS Antonio Campafia Bandranas, Barcelona, Spain No Drawing. Application May 19, 1943, Serial N0. 487,646

1 Claim. (01. 117-1) The production of documents of personal identity, which presents full guarantee against counterfeiting, has been and is still the object of trials and essays, in order to avoid any alterations of such documents, especially regarding the .teXt and photographs, which constitutes the basis of identification of the holder of same.

Therefore, numerous methods used in order to avoid the counterfeiting to be easily performed, have been tried in order to get a sure method of impeding those falsifications of signatures, imitations of the seals and clandestine reproduction of wordings and photographs, generally employed in this kind of documents. Notwithstanding, up to the present time, there has not been obtained any kind of document of identity, which is completely guaranteed against counterfeiting.

All these defects have been studied and after many experiments based in the circumstances there has been produced document of the kind described, which cannot be counterfeited.

The method to be employed will be described in the following specification which sets forth all the steps thereof.

The method is based essentially on the fact of coloring by an aqueous bath the photographic paper, employed in the manufacture of those documents, and it may be applied as well before or after the printing of same or even after being being completely finished. This coloring of the document has the object to avoid any counterfeiting or violation of the authenticity thereof and the process will be successful even if the paper is immersed in a bath formed by a material which suffers rapid discoloration in presence or in contact with hypochlorites, permanganates, oxalates, and in short, with all the agents used to efface or to eradicate ink.

By this method any attempt that may be tried 'to falsify or adulterate a document treated in the form beforesaid would be instantly obvious by the discoloration. The method to be employed according to this invention for the production of documents 'of identity that are impossible to be I counterfeited is now disclosed.

The document is prepared by means of a current photographic paper or if desired of a special kind of paper. Together with the photograph of the person there may be reproduced the text and wordings and also the seals and finger impressions, or there may be reproduced only part of same photographically and printed or written the remaining part.

Also the bath may be applied as well directly to the support as to the paste, of which the paper is manufactured or to the gelatine or photographic emulsion or finally to the finished document.

The material employed for the bath consists of a solution of phenosafanine 1:10,000 approxi--' mately.

The duration of the bath may be of about five minutes more or less, as to obtain a coloration which will be efiicacious and homogeneous.

It is to be understood that the details of the method may vary in practice, without altering or modifying the essential idea of this invention, the principal characteristics of which are contained in the following claim.

What I claim is:

The method of treating a material and the substances entering into the production of such material for the manufacture of photographic paper for preventing counterfeiting thereof, said method consisting of producing a coloring bath comprising a solution of phenosafanine to 1: 10,000, and immersing the material in said bath for a period of approximately five minutes to obtain the required coloringjor the material,

ANTONIO CAMPANA BANDRANAS. 

